Question

percent of change
answer each question.

1. sonya’s heart rate was 76 beats per minute. she ran a mile on her treadmill and checked her heart rate again. this time, her heart rate was 133 beats per minute. what was the percent increase in sonya’s heart rate?
2. last year, a taco truck ordered 3,000 pounds of cheese. this year, they ordered 2,100 pounds of cheese. what was the percent decrease in the pounds of cheese the taco truck ordered?
3. there were 425 people at the lincoln county high school football game last week. this week, 357 people attended the game. what was the percent decrease in attendance?
4. isaac is growing a tomato plant. when he measured his plant in june, it was 4.5 inches tall. by july, it was 11.25 inches tall. what was the percent increase in the height of isaac’s tomato plant from june to july?

remember:
to find the percentage:
\\(\frac{part}{whole} \times \frac{100}{1}\\)
(ext: i had $10 now i have $15, what was the percentage increase?
15 - 10 = 5 ← part
↑ whole
\\(\frac{5}{10} \times \frac{100}{1} = \frac{500}{10} = 50\\)
(50%) increase

Explanation:

Problem 1:

Step1: Find the change in heart rate

The initial heart rate is 76 beats per minute, and the new heart rate is 133 beats per minute. The change is \( 133 - 76 = 57 \).

Step2: Calculate the percent increase

Using the formula for percent change: \( \text{Percent Increase} = \frac{\text{Change}}{\text{Original}} \times 100 \). Substitute the values: \( \frac{57}{76} \times 100 \). Simplify \( \frac{57}{76} = 0.75 \), then \( 0.75 \times 100 = 75 \).

Step1: Find the change in cheese pounds

Last year's order was 3000 pounds, this year's is 2100 pounds. The change is \( 3000 - 2100 = 900 \).

Step2: Calculate the percent decrease

Using the percent change formula: \( \text{Percent Decrease} = \frac{\text{Change}}{\text{Original}} \times 100 \). Substitute: \( \frac{900}{3000} \times 100 \). Simplify \( \frac{900}{3000} = 0.3 \), then \( 0.3 \times 100 = 30 \).

Step1: Find the change in attendance

Last week's attendance was 425, this week's is 357. The change is \( 425 - 357 = 68 \).

Step2: Calculate the percent decrease

Using the formula: \( \text{Percent Decrease} = \frac{\text{Change}}{\text{Original}} \times 100 \). Substitute: \( \frac{68}{425} \times 100 \). Simplify \( \frac{68}{425} = 0.16 \), then \( 0.16 \times 100 = 16 \).

Answer:

75%

Problem 2: